1. Field of Invention
The device described herein relates generally to the production of oil and gas. More specifically, the present disclosure relates to a system and method for acoustically measuring the nozzle depth of a casing annulus remediation system.
2. Description of Related Art
Hydrocarbon producing wellbores have casing lining the wellbore and production tubing suspended within the casing. Some wellbores may employ multiple well casings of different diameters concentrically arranged in the wellbore. In some instances, a casing string may develop a leak thereby pressurizing an annulus between the leaking casing string and adjacent casing. Other sources of leaks include tubing, packers, wellhead packoffs, and faulty casing cement bond.
Pressure in the annulus can be controlled by introducing a high specific gravity fluid into the annulus, thereby isolating the wellhead from the pressure. In addition to adding fluid directly to the top of the annulus through a wellhead, hydraulic hose systems have been used to inject fluid into the pressurized annulus. The hose generally includes a nozzle element lowered proximate to the annulus bottom where the fluid is discharged from the hose. Typically the hose is stored on a reel from which it is unrolled, and then inserted through an entry in the wellhead. Although the hose may be stiffened with internal pressure, it may still bend when forced through the labyrinth of turns encountered between the wellhead and annulus. Tight tolerances in the annulus may also contribute to hose bending. Thus the “effective” length of hose inserted may not correlate to the length of hose taken from the reel.